At a dinner out last night, I was surprised to get a good mouthful of grit in my glass of sparkling wine. Looking down, we saw a good amount of powder (the consistency and color of salt) in the bottom of the glass. We mentioned this to the waitress and she took my glass away, then brought it back saying "We think it's just sediment from the wine. But we're giving you half-off your wine." We weren't expecting a discount (I would have been fine with just getting a new glass, honestly, which she did not provide.) But my question is, could it possibly have been sediment? I have never heard of such a think w/ sparkling wine and have had perhaps a thousand bottles over the years. I assumed the riddling and disgorgement would take care of that.